#!/bin/bash
#
# Once run the script, no need to run ./install.sh for testing. ;)
# Without an argument, this will install only normal variant.
# Valid arguments are:
#
#   compact dark dark-compact light light-compact all uninstall
#
# FIXME: `unity` and `xfwm4` are not fully supported for now since `*.svg` link incorrect locales (with '-light' variant).
# FIXME: Multiple arguments should be allowed.
set -ueo pipefail

REPO_DIR=$(cd "$(dirname "$0")" && pwd)
SRC_DIR=$REPO_DIR/src

DEST_DIR=$HOME/.themes
THEME_NAME=Flat-Plat-Blue.dev
# shellcheck disable=SC2034 # will this be used later?
COLOR_VARIANTS=('' '-dark' '-light')
# shellcheck disable=SC2034 # will this be used later?
SIZE_VARIANTS=('' '-compact')

GTK_VERSIONS=('3.18' '3.20' '3.22')
GS_VERSIONS=('3.18' '3.24' '3.26' '3.28')
LATEST_GS_VERSION=${GS_VERSIONS[-1]}

# Set a proper gnome-shell theme version
if [[ $(which gnome-shell 2> /dev/null) ]]; then
  CURRENT_GS_VERSION=$(gnome-shell --version | cut -d ' ' -f 3 | cut -d . -f -2)
  for version in "${GS_VERSIONS[@]}"; do
    if (( $(bc <<< "$CURRENT_GS_VERSION <= $version") )); then
      GS_VERSION=$version
      break
    elif (( $(bc <<< "$CURRENT_GS_VERSION > $LATEST_GS_VERSION") )); then
      GS_VERSION=$LATEST_GS_VERSION
      break
    fi
  done
else
  GS_VERSION=$LATEST_GS_VERSION
fi

test() {
  local color=$1
  local size=$2

  [[ "$color" == '-dark' ]] && local ELSE_DARK=$color
  [[ "$color" == '-light' ]] && local ELSE_LIGHT=$color

  local THEME_DIR="${DEST_DIR:?}/$THEME_NAME$color$size"

  # SC2115: Protect /.
  [[ -d "$THEME_DIR" ]] && rm -rf "${THEME_DIR:?}"

  mkdir -p                                                              "$THEME_DIR"
  ln -sT "$SRC_DIR/index$color$size.theme"                              "$THEME_DIR/index.theme"

  mkdir -p                                                              "$THEME_DIR/gnome-shell"
  ln -s  "$SRC_DIR/gnome-shell/"{extensions,pad-osd.css}                "$THEME_DIR/gnome-shell"
  ln -sT "$SRC_DIR/gnome-shell/assets${ELSE_DARK:-}"                        "$THEME_DIR/gnome-shell/assets"
  ln -sT "$SRC_DIR/gnome-shell/$GS_VERSION/gnome-shell$color$size.css"  "$THEME_DIR/gnome-shell/gnome-shell.css"

  mkdir -p                                                              "$THEME_DIR/gtk-2.0"
  ln -s  "$SRC_DIR/gtk-2.0/"{apps.rc,hacks.rc,main.rc}                  "$THEME_DIR/gtk-2.0"
  ln -sT "$SRC_DIR/gtk-2.0/assets${ELSE_DARK:-}"                            "$THEME_DIR/gtk-2.0/assets"
  ln -sT "$SRC_DIR/gtk-2.0/gtkrc$color"                                 "$THEME_DIR/gtk-2.0/gtkrc"

  for version in "${GTK_VERSIONS[@]}"; do
    if [[ "$version" == '3.18' ]]; then
      mkdir -p                                                          "$THEME_DIR/gtk-3.0"
      ln -s  "$SRC_DIR/gtk/assets"                                      "$THEME_DIR/gtk-3.0"
      ln -sT "$SRC_DIR/gtk/$version/gtk$color.css"                      "$THEME_DIR/gtk-3.0/gtk.css"
      [[ "$color" != '-dark' ]] && \
      ln -sT "$SRC_DIR/gtk/$version/gtk-dark.css"                       "$THEME_DIR/gtk-3.0/gtk-dark.css"
    else
      mkdir -p                                                          "$THEME_DIR/gtk-$version"
      ln -s  "$SRC_DIR/gtk/assets"                                      "$THEME_DIR/gtk-$version"
      ln -sT "$SRC_DIR/gtk/$version/gtk$color$size.css"                 "$THEME_DIR/gtk-$version/gtk.css"
      [[ "$color" != '-dark' ]] && \
      ln -sT "$SRC_DIR/gtk/$version/gtk-dark$size.css"                  "$THEME_DIR/gtk-$version/gtk-dark.css"
    fi
  done

  mkdir -p                                                              "$THEME_DIR/metacity-1"
  ln -s  "$SRC_DIR/metacity-1/assets"                                   "$THEME_DIR/metacity-1"
  ln -sT "$SRC_DIR/metacity-1/metacity-theme-2${ELSE_LIGHT:-}.xml"          "$THEME_DIR/metacity-1/metacity-theme-2.xml"
  ln -sT "$SRC_DIR/metacity-1/metacity-theme-3${ELSE_LIGHT:-}.xml"          "$THEME_DIR/metacity-1/metacity-theme-3.xml"

  mkdir -p                                                              "$THEME_DIR/unity"
  ln -s  "$SRC_DIR/unity/"{*.svg,*.png,dash-widgets.json}               "$THEME_DIR/unity"
  ln -sT "$SRC_DIR/unity/assets${ELSE_LIGHT:-}"                             "$THEME_DIR/unity/assets"

  mkdir -p                                                              "$THEME_DIR/xfwm4"
  ln -s  "$SRC_DIR/xfwm4/"{*.svg,themerc}                               "$THEME_DIR/xfwm4"
  ln -sT "$SRC_DIR/xfwm4/assets${ELSE_LIGHT:-}"                             "$THEME_DIR/xfwm4/assets"

  echo Installed to "$THEME_DIR"
}

case "${1:-}" in
  "")
    test '' ''
    ;;
  compact)
    test '' '-compact'
    ;;
  dark)
    test '-dark' ''
    ;;
  dark-compact)
    test '-dark' '-compact'
    ;;
  light)
    test '-light' ''
    ;;
  light-compact)
    test '-light' '-compact'
    ;;
  all)
    test '' ''
    test '' '-compact'
    test '-dark' ''
    test '-dark' '-compact'
    test '-light' ''
    test '-light' '-compact'
    ;;
  uninstall)
    # SC2115: Protect /.
    rm -rf "${DEST_DIR:?}/$THEME_NAME"{,-compact,-dark,-dark-compact,-light,-light-compact}
    ;;
  *)
    echo "Invalid argument: ${1:-}"
    echo "Valid arguments are: compact dark dark-compact light light-compact all uninstall"
    ;;
esac
